
<script language="javascript">
function initializeBody(){      	
      	// Seteo de proyecciones
		projection = new OpenLayers.Projection("EPSG:900913"); 
       	displayProjection = new OpenLayers.Projection("EPSG:4326");

		mapOptions = {
                projection: projection,
                displayProjection: displayProjection,
                units: "km",
                maxExtent: new OpenLayers.Bounds(-20037508, -20037508, 20037508, 20037508.34)
        };
		
        map = new OpenLayers.Map('map_canvas', mapOptions);
		 	
           	var veroad = new OpenLayers.Layer.VirtualEarth(
                "Virtual Earth Roads",
                {'type': VEMapStyle.Road, 'sphericalMercator': true}
            );
            var veaer = new OpenLayers.Layer.VirtualEarth(
                "Virtual Earth Aerial",
                {'type': VEMapStyle.Aerial, 'sphericalMercator': true}
            );
            var vehyb = new OpenLayers.Layer.VirtualEarth(
                "Virtual Earth Hybrid",
                {'type': VEMapStyle.Hybrid, 'sphericalMercator': true}
            );
 
 						
            map.addLayers([veroad, veaer, vehyb]);

		
		//selector de tipo de mapa
		var selectMapMenu = new OpenLayers.Control.SelectSwitcher({buttonText:'Mapa', width:'100px'});
		selectMapMenu.addItem('Calles', function(){map.setBaseLayer(veroad);});
		selectMapMenu.addItem('Aereo', function(){map.setBaseLayer(veaer);});
		selectMapMenu.addItem('Hibrido', function(){map.setBaseLayer(vehyb);});			
		map.addControl(selectMapMenu);		
		
		}
		
function unloadBody(){
		
		}
</script>